Abstract:Let Ω ⊂ R N , N 2, be a bounded domain. We consider the following quasilinear problem depending on a real parameter λ > 0:where f (t) is a nonlinearity that grows like e t N/N−1 as t → ∞ and behaves like t α , for some α ∈ (0, N − 1), as t → 0 + . More precisely, we require f to satisfy assumptions (A1)-(A5) in Section 1. With these assumptions we show the existence of Λ > 0 such that (P λ ) admits at least two solutions for all λ ∈ (0, Λ), one solution for λ = Λ and no solution for all λ > Λ. We also study th… Show more
“…Therefore, the curve C bends to the left at λ = Λ. Appealing to the uniqueness and multiplicity result in [11] (see Theorems 1.2,1.3 and Proposition 8.3), we complete the proof of (3). If f is of the form (f 1), from property (4) and the global bifurcation theory of Rabinowitz (see [14]) we see that there exists (λ n , u n ) ∈ C and λ * > 0 such that λ n → λ * and u n (0) → ∞ (since C cannot "cross" the minimal solutions branch which is locally unique).…”
Abstract. In this article we study positive solutions of the equation −∆u = f (u) in a punctured domain Ω = Ω \ {0} in R 2 and show sharp conditions on the nonlinearity f (t) that enables us to extend such a solution to the whole domain Ω and also preserve its regularity. We also show, using the framework of bifurcation theory, the existence of at least two solutions for certain classes of exponential type nonlinearities.
IntroductionLet Ω ⊂ R 2 be a bounded domain with 0 ∈ Ω. Denote Ω = Ω \ {0}. Let f : (0, ∞) −→ (0, ∞) be a locally Hölder continuous function which is nondecreasing for all large t > 0. In this article we study the following problem:It is well-known from the works of Brezis-Lions [5] that if u solves (P ), then indeed u solves the following problem in the distributional sense in the whole domain Ω:. This leads us to the following two questions: (Q1) Can we find a sharp condition on f that determines whether or not α = 0 in (P α )?(Q2) If α = 0, is it true that u is regular (say, C 2 ) in Ω?We make the following Definition 1.1. We say f is a sub-exponential type function ifWe say f is of super-exponential type if it is not a sub-exponential type function. As a complete answer to question (Q1) we show (Theorem 2.1) that if f is of super-exponential type, then α = 0, and conversely (Theorem 2.2) that (P α ) has solutions for small α > 0 if f is of sub-exponential type.Similarly, we answer question (Q2) by showing that for any f of sub-exponential type, any solution u of (P 0 ) is regular(C 2 ) inside Ω (Theorem 3.1). Conversely, for f of super-exponential type with any prescribed growth at ∞ and behaviour for small t > 0, in Lemma 3.1 and Theorem 3.3 we construct solutions u of (P 0 ) that blow-up only at the origin. To our knowledge, the existence of such singular solutions has not been considered so far for super-exponential type problems. Theorem 3.2 should be contrasted with the results in [2] and [13]. Particularly in [13], the nonlinearity under study is of a model type, viz., f (t) = e t µ , µ > 0. These authors show
“…Therefore, the curve C bends to the left at λ = Λ. Appealing to the uniqueness and multiplicity result in [11] (see Theorems 1.2,1.3 and Proposition 8.3), we complete the proof of (3). If f is of the form (f 1), from property (4) and the global bifurcation theory of Rabinowitz (see [14]) we see that there exists (λ n , u n ) ∈ C and λ * > 0 such that λ n → λ * and u n (0) → ∞ (since C cannot "cross" the minimal solutions branch which is locally unique).…”
Abstract. In this article we study positive solutions of the equation −∆u = f (u) in a punctured domain Ω = Ω \ {0} in R 2 and show sharp conditions on the nonlinearity f (t) that enables us to extend such a solution to the whole domain Ω and also preserve its regularity. We also show, using the framework of bifurcation theory, the existence of at least two solutions for certain classes of exponential type nonlinearities.
IntroductionLet Ω ⊂ R 2 be a bounded domain with 0 ∈ Ω. Denote Ω = Ω \ {0}. Let f : (0, ∞) −→ (0, ∞) be a locally Hölder continuous function which is nondecreasing for all large t > 0. In this article we study the following problem:It is well-known from the works of Brezis-Lions [5] that if u solves (P ), then indeed u solves the following problem in the distributional sense in the whole domain Ω:. This leads us to the following two questions: (Q1) Can we find a sharp condition on f that determines whether or not α = 0 in (P α )?(Q2) If α = 0, is it true that u is regular (say, C 2 ) in Ω?We make the following Definition 1.1. We say f is a sub-exponential type function ifWe say f is of super-exponential type if it is not a sub-exponential type function. As a complete answer to question (Q1) we show (Theorem 2.1) that if f is of super-exponential type, then α = 0, and conversely (Theorem 2.2) that (P α ) has solutions for small α > 0 if f is of sub-exponential type.Similarly, we answer question (Q2) by showing that for any f of sub-exponential type, any solution u of (P 0 ) is regular(C 2 ) inside Ω (Theorem 3.1). Conversely, for f of super-exponential type with any prescribed growth at ∞ and behaviour for small t > 0, in Lemma 3.1 and Theorem 3.3 we construct solutions u of (P 0 ) that blow-up only at the origin. To our knowledge, the existence of such singular solutions has not been considered so far for super-exponential type problems. Theorem 3.2 should be contrasted with the results in [2] and [13]. Particularly in [13], the nonlinearity under study is of a model type, viz., f (t) = e t µ , µ > 0. These authors show
“…The study of Palais-Smale level is also delicate due to the effect of discontinuous nature of the sublinear term. We use sequence of Moser functions with variable support as in [12] to obtain the Palais-Smale sequence below the critical level. Here we would like to mention that the results obtained are new even for the case β = 0.…”
Section: H(u)mentioning
confidence: 99%
“…Existence results for semilinear equation with continuous and exponential nonlinearity motivated from Moser-Trudinger inequality has been extensively studied starting from [1][2][3]10]. The combined effects of concave and convex nonlinearities are studied in the beautiful work of Ambrosetti et al [4] for critical exponent problems and these results are discussed for the exponential nonlinearities in [12].…”
Abstract. Let Ω be a bounded domain in R 2 with smooth boundary. We consider the following singular and critical elliptic problem with discontinuous nonlinearity:where 0 ≤ q < 1, 0 < α ≤ 4π and β ∈ [0, 2) such that≤ 1 andUnder the suitable assumptions on m(x, t) we show the existence and multiplicity of solutions for maximal interval for λ.
“…In [7] different than our techniques, such as elliptic estimates, variational methods or comparison principles are used. The variational approach of [7] is based on the application of the mountain pass geometry.…”
Section: Introductionmentioning
confidence: 99%
“…In [7] different than our techniques, such as elliptic estimates, variational methods or comparison principles are used. The variational approach of [7] is based on the application of the mountain pass geometry. The abstract approach, although in a sublinear case and with different type of nonlinearity is investigated in [2] but this applies only for such differential operators that can represent a duality mapping between suitable spaces.…”
ABSTRACT. We prove an existence principle that would apply for elliptic problems with nonlinearity separating into a difference of derivatives of two convex functions in the case when the growth conditions are imposed only on the minuend term. We present abstract result and its application. We modify the so called dual variational method.
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